Wireless transmission and reception



Feb. s, 1927.

R. A. FESSENDEN WIRELESS TRANSMISSION AND RECEPTION Fiied oct. 1:5. 1924 and rance; and more especially in wireless Fatent Feb. 8, 127.

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WIRELESS TRANSMISSION D.RECEBTIN.'

'application aree @maar is, 192e. senat at. feasts.;

telephonl;7 and broadcasting.

t has for its object increased eliiciency, freedom from disturbances,fincreased selectivity and range, and convenience in operation and cheapness.

Figures l and 2 shew, partly diagrammatically, apparatus adapted for carrying out my invention. Fig. 1 shews how the waves are transmitted and received; and Fig. 2 shews a reception device in more detail.

This invention relates to further develvo ments lalong the lines of applicants previous patents, U. 'S. 956,489--June 21st, 1906; 974,762-Jan. 14th, 1907; 1,015,881- Dec. 19th, 1906; British-2955, 190s; and others. y

Heretofore in the practice of the art of wireless signaling it has been the practice touse for transmission and reception waves -having their electric component perpendicuv lait, or in fa plane perpendicular to the waeiirths surface. The 'reason for this is. that if the antennaa wires are placed parallel Ato the earth there will be substantially 'no radiation in a plane at right angles to the antenna and to the earths surface; in fact the antenna then acts as a directional antenna in a plane containing the antenna and at right angles to the earths surface.. lThis -is well known and is shewnin applicants German Patent 225,256-Jan. 14th,

1907; and the methods therein shewn are' used extensively and known as the wireless compass.

So far as applicant knows no attempt has been made to use waves having their electrical component parallel to the earth with the exception of British Patent 2955, 1908 referred to'above; and this, while operating well for its limited purpose, was very wasteful of power and had but short range. The experience of others has no doubt been similar.

-But during the course of some .experiments during thel late war it occurred to applicant that it would be of interest .to see if a beam of waves having its electrical component parallel to the earths surface plane of the paper, iir Fig` l.

would act dierently. 0n trying 'the cirperiment .it was 'found that the previous excessive absorption no longer occurred, especially when the'rellector was so tilted that .the beam of waves was slightly inclined away from the'earths surface; as shewn in Fig. 1; 'where the electrical component is perpendicular to the plane of the paper. lfn

fact the transmission was found to be much better than with the usual way, in which the electrical component is parallel to the It was found that it was not necessary that the beam should be inclined away from the earths surface, as if the reflector was slowly tilted nodes of alternate large 'range and small range were found to occur, especially ifa sheet of copper were laid on the ground beneath and in .front of the'reilector.A

It was also .found that the eli'ect was somewhat better, onv many occasions convery greatly, and at times entirely. lt was,

also found'that the beam of waves so emitted was not absorbed to the same extent by the Heavysidelayer, (for explanation-of evidence of the existence of this layer-see Electrical Review, London, May 11th and 18th, 1906; Trans. Amer. Inst. Elec. Eng. July, 1908; Electrician, London, Dec. 19th, 1919; Popular Radio, November, 1923) the turning of the plane of polarization through a right angle from that hitherto used appearing` to greatly diminish the absorption and reflection losses and scattering.. And the fact that other stations operated with the plane of 'polarization perpendicular to the earth, greatly diminished their disturbing effect on the receiving station .of the present system, which is arran d to receive waves transmitted withthe p ane pf polarization, i. e. the plane 'of the electrical component of the waves, substantiallyparallel to the type shewnin applicants projector patents 'referred to above, o'r of other fo/rm, as well known inthe art,.or of the type `shewn at 10, 10', Fig. 2. The source of oscillations is shewn at 4, and 5, 5 are the leads thereto from the antenna.

T hereector 3, may be either of the 'para- I bolic spherical or cylindrical forms, accordother words, substantially as disclosed in applicants companion application, Serial No. 532,489,'filed Jan. 28, 1922, where the wave length is disclosed as above one meter and below fifty meters. This application is a continuation-impart of said application, 'Serial No. 532,489.

. Means vfor generating `waves of short .wave length are well known in the art, e. g. as shewn in applicants patents referred to above, and in applicants application Ser. No. 532,489, applicants Patents 793,777; 923,963; ,et al; applicants papers in Nature and elsewhere; and have been used successfully by.himself and by others. See Electrician, London,.May 19th, 192,2, for production of 3 meter waves with applicants compressed -gap `transmitter and Austins ape `in Bureau vof Standards' ftechnical pu hea tions, May, 1907 on one of la plicants compressed gasl gaps loaned the ureau for :purposes of tests. the DeForest threeelectrede hot cathode tube, as is well lknow-n Lemma in the art..` Also the hot cathode oscillator.

tube of applicant shewn inA va plicants specification, Ser. llo. .423,185, led Nov. 10th, 1.920. This, which is a development oiapplicants former types, shewn in U. S. pplication' 222,301, Aug. 26th, 1904, and

s. ,Patents 915,280 and 1,133,435,is .pa l

lculiarlyada-pted to the production of short wave engths, --for with v A'short wave lengths the extremely equencycurrents lowing in the vhot-cathode -are confined much =more to the surface than with the usual frequencies, and hence the eiliciency is.

muchincreased as much .lessfcathode has to -be'heated, i. e. much; yless 'of the. mass of lthe cathode or much lless conductor, Iand the responseisl better.. Moreover, =by making nodes in the cathode conductor and placing-the anode in suitable position opposite ,I one of the nodes, ormore than one, the

.his. last described method zand apparamsv i'snt. claimed in the resent aplication;

' The reflector fis pre erably t ted slightly or beneath it, as described above, are reflected antenna, as shewn .at l0, 10, Fig.' 2, may. A

`be used. 0r, as shewn in Fig. 1, aloop antenna, suitablytuned and with capacity, as is well known -in the art, described for example in applicant-s German Patent 225,- 256; Jan. 14th, 1907; and elsewhere. This is shewn more in detail in Fig. 2. 4The loop is supported in any suitable Way, -nor- Imally in a orizontal plane,by the leads 12, 12 offl stili' wire attached to the insulating support 13, so that 'the loop 7 may be rotated and tilted in any Vdesired way. The receiving apparatus 8 may be of a y ofthe well known s, suchvas are us or a're suitable for receiving the waves -of the e used, 4i. e. wireless waves, o f short lengt preferably.

In ,place of 'the loop'? a receiving reflector, preferably similar =to3 may be used; the 4re-., ceiving antenna may be similar to 10, 10 of Fig. 2, 'and-the leads 1 1, 11 attached to a receiving apparat f e 8.

The used 'as' iving apparatuses shewn 1n -v ig. 1, .hasthe advantage for some purposes thatdit will receive from all directions in the fearths horizontal plane and at the same time not be :responsive -to disturbances coming from overhead. [t may also be used Vto cutout any gparticularset of 'dis-- turbin influences by congoining with it the `shortorizo'ntal antenna 10, 10' as shown.

in 2; which :is preferably formed of fa :pair of vknobs 10, 10 `and a pair of rods,

.9, 9. When used for-antenna inconjunction with a reflector, as shewn at 3, 10", 1, the knobs may .be omitted, as they slig tly increase the size of the reflector nry for equal definition` of beam.

This method of horizontal 5 lane polarization has many :advantagesas ascribed above. It isespecially valuable in broadcasting, as :powerful stations near-by .may use, the lone horizontal, andthe other vertical, polarization, and listeneis-in -near 'by may use the `oppositely polarized receiving sets. I. e, a 'receiver usin a vertically ypola'rizxed antenna apparatus o the usual' type will not be substantially interfered with by "a high' Vhorizontally polarized sending station. 'It also enables those Avusing loop recaption to listen in simultaneously Yto all enjoying freedom 'from Static, and hence is especially suitable for marine Work and inter-subscriber ,communication and the like. And at the same time, by the use of the method shewn in appli- .cants Patents, c. g. 727 ,329, Mar. 14th, 1903; 7 52,895, Mar. 14th, 1903; ct al. may operate directionally` lVhere thc horizontal loop or coil antenna, as i. e. of the type described, and shewn at 7, Figs. 1 and 2, is used for emitting Waves as in broadcasting, the coil or loop is preferably placed on thc top of a high vpole and at a distance from absorbingbodies which might act as above described, prej-l udicially, in the caseof the projector described above.

What I claim is 1. ln Wireless signaling, the method of increasing the reliability of operation and diminishing errors and disturbance, which comprises transmitting the wireless signals by horizontally polarized Waves projected from the sending station at an angle sub- -waves at the receiving station at an angle substantially inclined to the plane of the earths surface at said receiving station.

3. In Wireless signaling, the method of increasing the reliability of operation and diminishing errors andl disturbance, which comprises transmitting the Wireless signals by horizontally polarized Waves projected from the sending station at anangle substantially inclined to the plane of the earths surface at said sending station and receivino said horizontally polarized Waves at the receiving station at an angle substantially inclined to the plane of the earths surface at said receiving stat-ion.

REGINALD A. FESSENDEN. 

